44 F.2d 306 (6th Cir. 1930), 5559, Seymour v. Ford Motor Co.
|Citation:||44 F.2d 306, 7 U.S.P.Q. 182|
|Party Name:||SEYMOUR v. FORD MOTOR CO.|
|Case Date:||November 05, 1930|
|Court:||United States Courts of Appeals, Court of Appeals for the Sixth Circuit|
Joseph H. Milans, of Washington, D.C. (William J. Belknap, Clarence B. Zewadski,
and Whittemore, Hulbert, Whittemore & Belknap, all of Detroit, Mich., on the brief), for appellant.
F. L. Chappell, of Kalamazoo, Mich. (Charles R. Halbert, of Detroit, Mich., I. Joseph Farley, of New York City, and Longley & Middleton, of Detroit, Mich., on the brief), for appellee.
Before DENISON, HICKS, and HICKENLOOPER, Circuit Judges.
HICKENLOOPER, Circuit Judge.
Appellant brought his action in the District Court for infringement of patent No. 1,277,652, for a gearing, issued September 3, 1918, to Seymour, upon division of a prior application filed September 9, 1913. The court below dismissed the bill of complaint 'for want of equity,' after rendering an opinion to the effect that the patent in suit involved only variation in degree from the prior art, that the disclosures had not advanced the art, and that the defendant's construction more closely approximated the prior art than that disclosed by the plaintiff. The opinion was rendered in response to defenses asserted by the appellee. The first ground for the dismissal of the plaintiff's bill we construe as a finding of want of invention or patentable novelty; the second suggests lack of utility; and the third savors of lack of infringement, although it is not expressly held that the claims have not been infringed, if they are to be held valid.
The patent relates to gear wheels, one of which is driven by the other, and which are adapted and used to be moved into, or withdrawn from, intermeshing relationship with each other. The purpose is to so construct the ends of the teeth of the gears that they may be shifted into interlocking relationship without tendency to chatter, without flat surfaces of the co-acting teeth coming into contact with each other, and so that only narrow edges of sliding contact are provided. The means for accomplishing this result, and for avoiding flat surface contacts of relatively substantial area, is to cut or bevel the flat end surfaces of the gear teeth, at different or variant angles. Claims 1 and 2 broadly define the invention, and are printed in the margin. 1
It had long been known in the prior art that an intermeshing of such gears would be greatly facilitated by this bevel or chamfer of the ends of the teeth, so that the axial motion of the tooth may start before the teeth reach the circumferential point of final engagement, and so that a substantial portion of the tooth of the driven gear may oppose an equally substantial portion of the driving gear at the moment of initial contact. Common practice was, however, to have the angles of bevel equal, as is shown in the French patent to Lefer, January 2, 1902, No. 317-502. In the United States patent to May, No. 309,236, December 16, 1884, the ends of the teeth are beveled upon both sides, so as to assist in meshing when the driving gear is rotating in either direction, thus making the ends relatively pointed, or curving to a point. Another form is shown in United States patent to Chard, No. 744,678, November 17, 1903, in which the teeth are beveled upon both sides on straight lines; the co-acting teeth of the two gears being beveled at the same angles. In order to prevent the breaking of sharp points at the contacting ends of opposite teeth, it had also been customary to leave a land or flat unbeveled portion of the tooth, and thus secure the advantages or beveling while avoiding frequency of damage to the teeth.
Seymour believed that with the teeth of the intermeshing gears cut at the same angle there was the danger of flat surface contacts with the jar and noise incident thereto, and that this might be avoided by cutting or beveling the teeth of the driving and the driven gears at different angles, thus producing a theoretical line or point contact, and avoiding the jar, noise, and friction incident to surface contacts (friction is of very minor significance, for even greater friction is developed after the teeth have passed the bevel but are still sliding into complete engagement). This he describes as beveling at variant angles. The situation is best understood by the diagram printed herewith, which shows the cross-section of the teeth, in a plane perpendicular to the radius of the gear wheel, as the teeth start upon the intermeshing operation. The first of these shows the bevel disclosed by Lefer; the second the device of May; the third shows the prior art teeth beveled at identical angles and with lands at the ends for greater durability; the fourth shows the Seymour design; and the
fifth the alleged infringing device. It will be noted that the latter has the teeth beveled at variant angles, but uses, upon both sets, the lands of the prior art. This...
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